已知-x+3y=5,求5(x-3y)²-8(x-3y)-5的值.

已知x.x+y.y-6x-8y+25=0,求3x.x+5y的值 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 已知x-2y=2016,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除以8x的值 已知x-2y=2012,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷8x的值 已知3x-2y/x+y=5/3求x；y的值 (1)已知x+y=6,x²-y²=5,求x-y的值（2）若x+y=3,x²+y² 已知：x-y=1,x+y=-7,求代数式3（x+y)+20(x-y)-5的值 已知-x+3y=5,求5(x-3y)²-8(x-3y)-5的值 1.已知:x-2y=3,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除4x 的值 已知x-2y=2011,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]÷4x的值. 已知X/Y=5/3,求X/(X+Y)+X/(X-Y)-Y*2/(X*2-Y*2)的值. 已知(x+y):y=8:3,求2x+5y/3x-y和x^2-xy/y^2+3xy的值